need help finding out if barrel is 556 or 223

AR/M4 AR General Discussion
1

Ok guys I got a barrel from a guy he said it was will shoot 556 and 223 buy he said it was never fired but I do not see any marks on the barrel that says what is chamber In. I have fired 223 and it fires fine . Also It looks like some gasses have leaked from where the gas tube goes in to the gas block

2

Well without some pics or other identifying marks there is no way for us to know.

3

Well what should I take pictures of ?

4

And the only mark at all is a single 2 on the outside of the chamber but my friend has a 6 on the same place on his spikes tactical upper so I’m guessing that has nothing to really do with what caliber it is

5

You need this:

http://www.m-guns.com/tools.php

556/223 chamber gauge.

6

Is there any only way to find out with out buying a tool ?

7

Nope.

8

I’ll just be honest. If there are no markings (make, model, etc…) then there is a high probability that you have some POS no name barrel and quite honestly I wouldn’t waste my time trying to polish a turd. Almost every quality barrel (and some that aren’t) have some markings for example;

  1. Colt= C MP 1/7 NATO 5.56

  2. FN= FNMI MP 1/7 NATO 5.56

  3. BCM= HP MP 1/7 NATO 5.56

  4. Bushmaster (ugh?) B MP 1/9 5.56

  5. Delton= DTI 1/7 5.56 NATO

I think you get the picture.

9

Ya I know all that I was just seeing if there was a way to find out with out tools I would just buy a green mountain barrels (plan to anyways but I don’t want to right now )

10

There are no marks underneath the handguards?

11

You could have a casting made of the chamber & leade. Another option is to take it to a good AR armorer and have them clean it up with a 5.56 reamer

12

TC2 the only mark is a 2 stamped on the chamber that’s all but my friend had a 6 in the same spot.

13

REM700FSTF,

I don’t think your getting the vibe of all the responses offered here, there is no real free way of checking your barrels chamber accurately unless a qualified AR armorer is willing to take the work on Pro-bono. Basically you had a error in judgment buying a unmarked mystery barrel and now your looking for a free fix which is not out there. Unless you have the barrels chamber slugged/reamed or maybe a really experienced AR armorer could ID the throat by sight but absent that your best recourse is to mark the barrel as .223 only and see if it likes steel cased.